The 12150FNB from eSource Optics is a Vacuum UV (VUV) optical bandpass filter that allows transmission at a peak wavelength of 150 nm. It has a bandwidth (FWHM) of 20 nm and wavelength tolerance of ± 2.5 nm. This optical filter has a minimum optical peak transmission of 15% and blocks approximately 10-3 UV through FIR. The edge chamfer of this optical filter measures nearly 0.5 mm x 45 degrees and has a clear aperture of 80% (central). It has an unmounted and open-faced design with a parallelism of 5 arc minutes. This narrowband optical filter has a diameter of 12.7 mm ± 0.25 mm and thickness of 1.5 mm - 5 mm.